The American actress landed the only win for the film, which had been nominated in four categories including Best Picture, Directing, and Adapted Screenplay.

Larson (26) has been acting since childhood and her performance in Room had already earned her several other gongs including the Golden Globe for Best Actress in a Motion Picture drama.

She paid tribute to Irish director Lenny Abrahamson and screenwriter Emma Donogue, who had both been nominated in their respective categories.

Best actress Brie Larson, "Room", and best actor Leonardo DiCaprio, "The Revenant", pose during the 88th Academy Awards in Hollywood, California February 28, 2016. REUTERS/Mike Blake

She also thanked her "partner through this", her nine-year-old co-star Jacob Tremblay and her real life partner Alex Greenwald.

“Thank you to the moviegoers. Thank you for going to the theaters and seeing our films," she concluded.

Meanwhile, Leonardo DiCaprio (41) finally won for his role in The Revenant and was met by fierce applause by the audience and his fellow nominees, including a beaming Michael Fassbender.

DiCaprio had previously been nominated five times but triumphed with his portrayal of real-life fur trapper Hugh Glass in Alejandro Gonzalez Inarritu's survival thriller, and he paid tribute to his collaborators as he stepped up onstage.

Best Supporting Actor Mark Rylance (L), Best Actress Brie Larson, Best Actor Leonardo DiCaprio and Best Supporting Actress Alicia Vikander (R) pose with their Oscars backstage at the 88th Academy Awards in Hollywood, California February 28, 2016. REUTERS/Mike Blake TPX IMAGES OF THE DAY

"Thank you all so very much...," Leonardo said. "To my brother in this endeavour, (co-star) Tom Hardy. Tom, your fierce talent onscreen can only be surpassed by your friendship offscreen.

"To Mr. Alejandro Inarritu, as the history of cinema unfolds, you have forged your way into history in these past two years; what an unbelievable talent you are..."